Boiler feed water control device



May 12, 1931. W, DOBLE 1,804,751

BOILER FEED WATER CONTROL DEVICE Filed CI'.. .6 1924 T .sa/ay TANK Avui/V70@ WH/PFE Do s L. E

/dla Avro/@ways 'A mmffw Patented May l2, '1193i IFJIRFEN DOBLE OF BERKELEY, CALIFORNIA, ASSIGNR TO DOBLE STEAM'. MOTORS CQRPORATION, OF WILMINGTON, DELAVARE, A. CRERATIGN OF DELAWARE vBQ'IIZER FEED- WATER CONTROL DEVICE Application filed ctober 6, 1924. Serial No. 742,036.

'Ihe invention relates to a device lfor controlling the rate at which water is introduced into a steam boiler.

An object of the invention is to provide t a device that will cause water to be introduced into a steam boiler' at a substantially constant rate, substantially regardless of the rate at which water is supplied by the feed water pump. t f Another object of the invention is to provide a device that will cause the introduction of water into a steam boiler at a substantially constant rate, by causing excess water pumped by the boiler feed pump to be bypassed back tothe water supply tank.

Another object of the invention is to pro vide an apparatus for controlling the rate of introduction of water into a steam boiler, which is adjustable so that the substantially constant rate may be taken at that value which comes nearest to satisfying the water input requirements of the boiler.

The invention possesses other ,advantageous features, someof which, with the fore- `going, will be set forth at length in the following description, wherein I shall outline in full that form of my invention which I have selected for illustration in the drawing accompanying and forming part of the present specification. In said drawing I have shown one form of apparatus embodying my invention, but it is to be understood that I do not limit myself to such form, since the invention, as set forth in the claim, may be embodied in a plurality of forms.

The drawing is a vertical section through the device of my invention. l

The device of my invention is particularly applicable for use in connection with the steam generating plant of a steam automobile or other vehicle. The device of my invention is interposed between the feed water pump and the steam generator and operates to cause the introduction of water into thesteam generator at a substantially constant rate, regardless ofvariations in the speed ofthe feed water pump. I have found it desirable to maintain the rate at which feed water is introduced into the boiler, substantially constant. The feed Water pump is preferably directly connected to the steam engine, which that the vehicle travels over varying grades,

it is not feasible to pass all of the Water discharged by the pump intothe boiler, since the engine, when the vehicle is travelling at a good speed on a level highway, might consume far less steam than when the vehicle is-climbing` a grade at a lower speed. The capacity of the pump is greater than the feed water requirements of the boiler, so that there is always available sufficient feed Water under pressure to meet the requirements of the boilerunder `varying loads and I have made the feed water pump of .such capacity that when the vehicle is climbing a steep grade at a low speed, it will pump ample water to meet the requirements of the boiler.

The function of the device of my invent-ion is to maintain the rate at which water is introduced into the boiler substantially constant, regardless of the speed of the pump. This is accomplished by by-passing various proportions of the water pumped, the amount of water by-passed being determined in part' by the speed of the pump.

The device of my invention comprises a casing 2 having a cylindrical chamber or Cylinder 3 therein. The cylinder is provided with an outlet passage 4 which is preferably connected to the water supply tank and the discharge of water through the passage 1 is controlled by the valve 5 which is preferably lformed integral with or secured to a piston 6 disposed in the cylinder 3. The valve 5 is normally held to its' seat, closing the outlet passage 4, by a spring 7 interposed between the piston 6 and the cylinder head 8. The

casing 2 is provided with a passage 12 open-- ing into the cylinder below the piston and being adapted to be connected at its other end to the feed water pump, so that the water discharged from the pump enters the passage 12. The casing is also provided with a passage 13 which opens at one end into the cylinder' 8 above the piston and which at its other end is adapted to be connected to the steam boiler, i so that the water discharging from the pas- 5 sagel 13 is introduced into the. boiler. The

passages 12 and 13 are connected by a passage 14 through which they water passes from the passage 12 to the passage 13 and the passage 14 is provided With means for controlling the rate of the passage of water there'- through. The passa-ge 14 is enlarged at its junction with the passage 13, to form a valve seat 15, and an adjustable valve lcooperates with the valve seat to provide an orifice or presence of the restricted passage or orifice, the pressure in the passage 14 will be reater than the pressure in the passage 13 an these two pressures are exerted respectively on opposite sides of the piston 6. The size of the orifice and the difference between these two restricted passage for the Water. Due to the` my hand.

WARREN DOBLE.

pressures, determines the ratey at which water passes the orifice and, by adj ustin the position of the valve 16, the rate at w ich water flows to the boiler may be varied.

When the speed of the feed water pump is increased to a magnitude at which an excess of water is being pumped, the difference in pressure on opposite sides of the orifice is increased and consequently the differential pressure on opposite sides of the piston is 'increased, causing the piston to be raised thus lifting the valve 5 from its seat, thereby per-Y mitting water to by-pass through the outlet passage 4 to the supply tank. The difference 1n pressure is thereby maintained substantially constant, so that the rate at which feed water is introduced into the boiler remains substantiall constant. The speed of the. pump may e increased indefinitely without materially increasing the rate at which water is introduced into the boiler, since an increase in speed of the pum will result in the discharge of an increase amount of water by the pump, which will in turn result in a further lifting of the valve 5, permitting a greater anxilpunt -of water to by-pass to the supply ta I have found this device to be quite accurate. I have found that as the rate of discharge of water from the feed pump increases, there-is a very slight and relatively immaterial increase in the rate at which feed water is introduced into the boiler, due to the increase of pressure in the passage 14, necessary to lift the piston 6 further against the action of the spring 7 This slight increase in pressure causes afslight increase in the rate of flow of water past the valve 16, but this slight increase has substantially no eiect upon the practicability and etliciency of the device.

I claim:

The combination with a body having therein a cylinder, a p. ing with said cy inder adlacent opposite ends air of conduits communicat- 

